wi-fi issues? airplay

[MattDLEA]

Im trying to get to the bottom of this.

Think there is two problems. One is we only have a 8mb connection coming in to school. --> we are trying to up the bandwidth as we regularly reach this limit and the network just goes to a crawl.

 

When I try to update the ipads with meraki, it takes ages and normally fails. Same if i go to the app store and try to download the apps that way ( pages update 20 mins to a hour) So I'm assuming that a more bandwidth into school would fix this?

 

The main problem is we have used airserver and now we are on apple TV's which the staff use to mirror the ipads to the projector. Randomy the airplay freezes then kicks the mirror off. I'm assuming this is a wifi problem as none of this traffic is leaving the school?

Both the apple TV and the ipads are connected wirelessly.

We currently have Netgear 360 N dual band AP's one per 2 classrooms roughly any ideas?

 

Thanks

[Abaddon]

How many iPads / Apple TV's do you have? This is quite likely to be a broadcast issue if you are not managing he Bonjour protocol in any way... Edited December 11, 2014 by Abaddon

[MattDLEA]

12 Apple TV's

250+ ipads

I don't think I'm managing Bonjour... at least not intentionally... erm what do I need to do

[Stuclark]

The issues you're seeing are all to do with AppleTVs; Bonjour and having a flat network (single VLAN / single broadcast domain). Your internet connection speed will have some bearing, but not as much as you think. Worry about that once you've done everything that's below.

 

Essentially, you've got to block the Bonjour traffic from flooding your entire network with junk broadcast traffic. You can't turn Bonjour off on Apple devices as it's the main network discovery tool they use.

 

Firstly, ATV is quite picky when using a WiFi connection - you need to make sure you've got good signal strength otherwise they have a tendency to drop connections. Anything under 8Mbps from the AP to the gateway is going to cause you trouble. *Please note, this is NOT the same thing as your internet connection speed*

 

Secondly, deploying more than about 10 ATVs on a single network (or I should say single broadcast domain) is a bad idea - the amount of Bonjour traffic they send out causes them to conflict with each other and randomly drop off the network altogether. *Bear in mind that iPads & iPhones also shout Bonjour traffic around a network, so 2 ATVs and 20 iPads on the same network will cause the same issues*

 

Thirdly, there's a great bug which causes the ATVs to randomly drop AirPlay connections to devices (we're mostly using iPads). This bug *isn't* caused by Conference Mode, as some have suggested, nor does it appear to be related to the screensaver timeout (we have screensavers disabled) but the outcome is the same - if you leave an iPad connected to an ATV for anything over about 5 minutes without any user input; the connection will be dropped and then you can't reconnect until you've rebooted the iPad. This last part is because the ATV, despite having dropped the connection, will then tell the iPad that someone else (you) is already connected!

 

We resolved most of these issues by segmenting our WLAN into 14 seperate "departmental" WLANs, each with an unique IP range (yet using the same WiFi controller) to reduce the number of ATVs that can see each other. The maximum we now have on any one WLAN is 14, which seems to be ok with the approx. 20 iPads that regularly connect to the same WLAN. (we've also limited the DHCP range to 65 devices to reduce the chances of flooding the networks). We're only broadcasting an individual WLAN to the area of the school where that subject it taught.

 

The downside of this approach is that we've had to provision more WiFi access points to ensure all our WLANs have good coverage, and teachers have to swap their iPads from the school's *main* WLAN to the departmental ones when they want to use an ATV - this is causing a couple of issues in other ways; but at least the ATVs seem to be mostly stable.

[ZeroHour]

Im trying to get to the bottom of this.

Think there is two problems. One is we only have a 8mb connection coming in to school. --> we are trying to up the bandwidth as we regularly reach this limit and the network just goes to a crawl.

 

When I try to update the ipads with meraki, it takes ages and normally fails. Same if i go to the app store and try to download the apps that way ( pages update 20 mins to a hour) So I'm assuming that a more bandwidth into school would fix this?

 

This is a bandwidth issue I suspect, 8mb is not very fast and pages for example can be a large update. Do you have any proxy/caching locally? you could set it up to hard cache anything from the Apple store for 24 hours (not sure of the paths/urls but I think its on here for smoothwall anyway) and then once its downloaded once the rest get it from the cache.

[Stuclark]

This is a bandwidth issue I suspect

As I said above, this is mainly NOT a bandwidth issue. No 8Mbps is not a lot, but that's not what's causing the Bonjour issues you're facing with the AppleTVs and iPads. Fix that first, then worry about the download speed from the interwebs

[MattDLEA]

How would you go about doing this?

We resolved most of these issues by segmenting our WLAN into 14 seperate "departmental" WLANs, each with an unique IP range (yet using the same WiFi controller) to reduce the number of ATVs that can see each other. The maximum we now have on any one WLAN is 14, which seems to be ok with the approx. 20 iPads that regularly connect to the same WLAN. (we've also limited the DHCP range to 65 devices to reduce the chances of flooding the networks). We're only broadcasting an individual WLAN to the area of the school where that subject it taught.

[Quackers]

How odd we do have a VLAN for the guest network, but the rest is flat, with 40 Apple TV's (which are all air played too all day long) , 120 Apple Macs and almost 200 iPads, with all our printers (40+) with Bonjour turned on and we don't have these issues. There is also another 300 Windows devices adding to the broadcast traffic. So it seems odd for it to being killed by just 12 Apple TVs and 200 iPads.

[MattDLEA]

I have no idea

[njc235]

A number of wifi manufacturers offer a Bonjour gateway which converts the broadcast packets to unicast to enable it to traverse the routed network without causing broadcast 'storms'. One example is here...Bonjour | Meru Networks

[Stuclark]

The whole point is you want to prevent any unicast packets getting out of the (local) network. So while they can be helpful in some instances, a Bonjour Gateway is not actually what you want here...

 

As I said in a PM earlier today:

I can't easily give specifics, because a lot of what you can achieve depends on what network (wired and wireless) hardware you have.

 

We run HP layer 3 switches everywhere for our LAN hardware, so I have fully routable VLAN abilities on them. We're also running AirTight for our wireless (used to be Aruba), so with both of them I have the ability to create different VLANs and assign them different SSIDs (essentially creating seperate WLANs) and broadcast those different SSIDs on whichever APs I chose.

 

The main points you will need to consider / work out are:

 

To stop the Bonjour traffic you need to have small, independent networks. The easiest way of doing this is to use VLANs which have unique IP ranges, ensuring they are not directly routable from one to the other (without going via something that will block broadcast traffic). This is the key!

 

To make it easy to use those VLANs, we then created "departmental" wireless SSIDs, so the "English" SSID connects to the "English" VLAN and can only see "English" AppleTVs. The "Maths" SSID connects to the "Maths" VLAN and can only see "Maths" AppleTVs etc.

 

If your APs are layer 2 only, you will need to configure your DHCP server(s) to issue IP addresses on each of the VLANs you're using and enable that on your core switches (this is usually a switch setting - something along the lines of "DHCP helper address") and you'll need to make sure your default (untagged) VLAN is visible for DHCP traffic on all the other VLANs (if all your VLANs use your main network switch as their gateway, you can create mulitple virtual gw addresses on the switch and then your DHCP addressing becomes quite easy). If your APs are layer 3 or "tunnel" like Arubas do, then you can create your VLANs and DHCP ranges on the wireless controller.

 

Once you've got those two elements set up, the rest should be quite easy.

[blundellm]

So why does this work in all its glorious simplicity on your network, while StuClark declares the need for a complex of vlans? Please provide further info about your network.

[Michael]

Downloading offline Apple iPad updates is the way to go, especially as you have so many devices.

 

The latest iOS8.1.2 *.ipsw files can be downloaded here

 

If Windows adds a *.zip file extension, rename this to *.ipsw. Within iTunes12 (on Windows) hold shift, click Update and select the correct file. You can also do the same in Yosemite + iTunes12, by holding Apple key + shift (I think, from memory).

 

This is going to save you a lot of time doing them in batches offline, rather than upgrading via your wireless.

[blundellm]

Or, for £400, buy a mac mini and set it up with the ability to deliver updates from a local cache. The first machine downloads the updates, the mac mini stores it and all subsequent devices get it from there - and once its set up, needs no attention.

[Brimstone]

Or, for £400, buy a mac mini and set it up with the ability to deliver updates from a local cache. The first machine downloads the updates, the mac mini stores it and all subsequent devices get it from there - and once its set up, needs no attention.

 

 

BUT....requires a static public I.P. address otherwise you will get even more issues than before......

[Brimstone]

12 Apple TV's

250+ ipads

I don't think I'm managing Bonjour... at least not intentionally... erm what do I need to do

 

 

With that many iPads and only an 8MB connection updates to iPads are likely to fail every single time....

[Stuclark]

Of course, as long as everyone keeps mixing up the two very different issues here, confusion is going to rein!

 

The "issue" of having only an 8Mbps internet connection means things are going to be slow downloading / browsing the internet. Thus Apple updates and things that come from the internet *for every single device* are going to fail. Yes, a local caching / proxy server of some sort will help to cure this.

 

The other issue, the one of AirPlay not working reliably, most definitely *IS* related to Bonjour traffic. If you have "40 Apple TV's (which are all air played too all day long) , 120 Apple Macs and almost 200 iPads, with all our printers (40+) [and] another 300 Windows devices" on a flat network, then I'm surprised you're not seeing network flooding issues caused by Bonjour. It could be because your network backbone is slower than ours (ours is 20GBps to each edge switch plus 1GBps to every device) or it could be that you don't have all those devices broadcasting Bonjour all day long. For the record, Windows computers don't broadcast Bonjour traffic around anywhere near as much as Apple devices do, mainly because Bonjour is not a feature of Windows unless you install some Apple software.

 

From our extensive testing (over a year) we have found that for ultimate reliability, you don't really want to have more than about 60 Apple devices on the same VLAN / network segment, otherwise you will see some problems.

[Michael]

I still think the issues are linked, as once the bulk of devices have been upgraded to iOS8.1.2, this should free up bandwidth for other applications - be it Apple TV or other.

 

I.T is a funny thing - in the context of Windows, you can setup WSUS, but even I wouldn't push out Service Packs. They're too big and unreliable. Re-imaging from scratch is better with the Service Pack included. The same applies to iOS - seeing as Apple seem to release a new major iOS version every 12 months. Even with a monster of an internet connection, updating that many iPads over wireless, it just isn't realistic at over 1GB per device.

[blundellm]

BUT....requires a static public I.P. address otherwise you will get even more issues than before......

 

The pain to set this up is far less than the ongoing pain of finding, downloading and manually updating Mac updates. (I made my comment not knowing about your set-up. For us, a static IP was a given as we have our own leased line, which, I appreciate, not everyone has access to!)

[Alis_Klar]

Apple seeks standard to appease angry university net managers | Network World

[blundellm]

Apple seeks standard to appease angry university net managers | Network World ...

 

This article is dated 2012, and since then, what has happened? The problem remains...

[Alis_Klar]

Yes the problem still remains (for now) but you can mitigate the issues with off the shelf solutions from these vendors Xirrus, Aruba , Cisco, Aerohive and Ruckus.

[blundellm]

I'm with you there, but its clear Apple have no interest in making enterprise-scale deployments easier for anyone. Of course, with the profits they're posting, why would they give a damn when they are busy laughing all the way to the bank!